Roof vent pipe shield

ABSTRACT

A shield for protecting a roof vent pipe has an outer cylindrical sheath extending downwardly for a substantial distance with a substantially uniform outer diameter and terminating at the bottom in a flaring portion adapted to contact with the sealing base of the vent pipe. The upper end is inturned to form an inner cylinder extending downwardly for a distance substantially greater than the outer diameter of the outer cylinder. The vent pipe is thereby enclosed between the outer and inner portions of the shield. The shield is preferably molded from a non-metallic material such as polypropylene plastic.

United States Patent [191 Nievelt [111 3,797,181 [451 Mar. 19, 1974Related US. Application Data Continuation-impart of Ser. No. 490.382,Sept. 27, 1965, abandoned.

[56] References Cited UNITED STATES PATENTS 3/1930 Blanchard 52/244 X9/1940 Prince 4/1897 Weeden 52/58 X 1.202.687 10/1916 Elkerton i. 285/43X 1,923,220 8/1933 Lightbown 3,163,101 12/1964 Caparrelli 285/44 XPrimary ExaminerPrice C. Faw, Jr. Attg n y, gjgent, or Firr'nWhittemore,Hulbert & Belknap [5 7] ABSTRACT A shield for protecting a roof ventpipe has an outer cylindrical sheath extending downwardly for asubstantial distance with a substantially uniform outer diameter andterminating at the bottom in a flaring portion adapted to contact withthe sealing base of the vent pipe. The upper end is inturned to form aninner cylinder extending downwardly for a distance substantially greaterthan the outer diameter of the outer cylinder. The vent pipe is therebyenclosed between the outer and inner portions of the shield. The shieldis preferably molded from a non-metallic material such as polypropyleneplastic.

10 Claims, 6 Drawing Figures PATENTEU NARIQ l974 INVENTOR FRANK J.NIEVELT ATTORNEYS ROOF VENT PIPE SHIELD This application is acontinuation-in-part of Ser. No. 490,382 filed Sept. 27, 1965 nowabandoned.

The invention relates to a new and improved roof vent pipe shield.

Under the building and plumbing codes of various cities it is alwaysrequired that for each plumbing fixture trap, a vent pipe be connectedthereto which extends through the roof. The structures which arecommercially available to builders for complying with the codes havebeen standardized to a considerable extent but in general they consistof a sheet metal base secured to the roof in a manner which isconsidered leakproof. There is an upstanding collar on the base of asufficiently large inner diameter to permit the vent pipe to extendupwardly therethrough for whatever is prescribed by the code. The usualpractice is to provide caulking between the collar and the vent pipe tomake it leakproof. However, it is quite well known that these standardconstructions, while usually leakproof when first installed, often laterdevelop flaws which result in leakage of rain water. There have beenmany proposals for suppyling a shield for theyent pipe and theconstructions heretofore available have met with various degrees ofsuccess. The present invention'is an improvement in shields for roofvent pipes.

In the drawing:

FIG. 1 is a perspective view showing a standard construction of roofvent pipe with the improved shield in position to be applied thereto.

FIG. 2 is a vertical section through the vent pipe and shield.

FIG. 3 is a cross section on the line 3-3 of FIG. 2.

FIG. 4 is a cross section on the line 4--4 of FIG. 2.

FIG. 5 is an elevation showing the lower portion of the vent pipeshield.

FIG. 6 is a longitudinal section through a modified construction ofshield.

As shown in FIG. 1, the numeral 10 shows, in perspective, theexterior ofthe shield of the invention in position to be inserted over a roof ventpipe 11 which extends upwardly from the roof 12. The vent pipe 11 isnormally manufactured in standard sizes designated by the insidediameter thereof, the usual standards being designated as 3-inch and4-inch. It is of course necessary that the shield of the presentinvention be constructed of a size to fit the particular size ofstandard vent pipe. In accordance with standard practice the vent pipeprojects through the collar 13 of the sheet metal base 14 which in turnis mounted beneath the shingles 15 of the roof in such a manner as toinsure a leakproof construction. The inner diameter 16 of the collar 13is sufficiently larger in diameter than the outside of the pipe 1 1 soas to permit substantial variations in tolerances in the mounting of thebase in the roof. Between the vent pipe and the inside diameter of thecollar it is conventional to provide caulking 17. The base 14 has a flatrectangular portion which contacts with the roof. Within the margins ofthe rectangular base there is a connecting dome-shaped portion 34 whichcurves upwardly until it intersects with the collar 13 thereby providinga curved convex surface 18. The dome has a somewhat different curvaturein the front portion 19 below the collar, than it has in the rearportion 20, and the two opposite side portions 21. The

construction as thus far described is standard practice in the art andthe present invention relates to a shield which is adapted to be used inconnection with said standard roof vent pipe construction.

The shield 10 is preferably made of a nonmetallic material which can bereadily molded into the ultimate configuration. The outside of theshield has a cylindrical portion 22 extending for the greater part ofthe total length with a flaring skirt portion 23 at the base. The innercylinder 24 extends downwardly from the top end 25 for a distancesubstantially greater than the outer diameter of the outer cylinder 22and the lower end 26 is at a distance substantially above the line 27forming the intersection between the flare 23 and the outer cylinder 22.The annular space between the inner and outer tubes of the shield issufficient to receive the standard vent pipe 11 with which the shield isdesigned to cooperate. The plastic parts 29 which are shown in FIG. 4 asbeing spaced circumferentially on the inside of the flaring portion ofthe shield are included for facilitating the manufacture of the device.These parts 29 are used during the molding process as abutmentsfacilitating the ejection of the molded article from the die.

As shown in FIG. 5, the lower end of the shield is arranged at an anglewith the longitudinal axis and the edge 30 has an angle corresponding toa standard pitch of a roof. In order that the shield may be adapted forroofs of different pitches a series of score lines are formed on theouter surface of the skirt 23, these lines being designated by thenumerals 31., 32 and 33 respectively. The angle of the base shown at 30is that which most nearly accords with the pitch of a modern roof. Theline 31 corresponds to a roof angle of 20 to 29. The line 32 correspondsto a pitch angle between 30 and 40, while the line 33 corresponds to anangle which would be considered a steep roof.

It will be observed that when the shield is placed over the vent pipethe lower edge 30 of the skirt portion of the shield is designed tocontact with the curved connecting portion 34 of the sheet metal base14. Since the curved connecting portion 34 of the sheet metal base issomewhat irregular in curvature the fit of the shield is obtained byreason of the flexibility of the skirt. This is obtained because of thenature of the material used for the shield and because the walls of theskirt portion are thin enough to permit flexing so that the skirt willconform precisely with whatever irregularities there may be in thecurved portion 34 of the base.

Although the invention is not necessarily limited to any specificmaterial, the shield of this invention is preferably manufactured from aplastic material which lends itself to injection molding. A suitablematerial is a polypropylene plastic such as a polypropylene copolymer.This material forms an all weather crackproof semi-flexible structurewhich can be readily trimmed if necessary to fit roofs of variouspitches. Desirably the polypropylene plastic contains a material forimparting a gold coloration.

Although the invention is not limited to particular sizes and dimensionsit should be noted that a 3-inch roof vent pipe is normally providedwith a sheet metal basein which the fiat portion has a width of about 11 inches and a length of about 12 inches. The inside diameter of thecollar 13 is about 3% inches, while the collar extends upwardly abovethe flat portion for about 2% inches at the vertical axis. The distancefrom the front intersection line 35 to the collar is about 3 inches,while the distance from the collar to the sides and upper line ofintersection is about 1 inch. The above figures represent a standardtype of sheet metal base for a 3-inch vent pipe. When larger sizes ofvent pipes are used the dimensions of the base are somewhat larger.

The shield of the present invention when manufactured to fit a standard3-inch vent pipe structure is desirably about 14 inches in length andthe cylindrical portion is 3% inches in outer diameter and2 /2 inches ininner diameter. The wall thickness throughout is approximately 1/16 inchand the upper edge 25 is /1 inch in thickness.

As previously stated, the inner cylinder 24 extends downwardly from thetop end 25 for a distance substantially greater than the outer diameterof the outer cylinder 22. This is clearly illustrated in FIG. 2.

The shield as herein above described can be used with vent pipes whichextend beyond the flashing and the collar for a distance from 2 inchesto 13 inches. The shield of this invention when used with a vent pipelarger than 3 inches is made correspondingly larger. The vent pipeshield of the present invention has many advantages over theconstructions which have heretofore been used to protect vent pipes.Amongst the advantages are the following: This device can bemanufactured at low cost by mass production methods. The material isflexible to fit irregular vent pipes. The inside sleeve 24 readilyslides within the vent pipe while the outside portion extends down ontothe metal flashing and protects against rusting of said metal flashing.The present construction is easy to install and because of the coloringincorporated in the plastic, it beautifies the roof and does not needperiodic painting although the material is adapted to receive paint ifso desired. Because of the nature of the material the shield forms alightning insulator, and the entire object is rustproof and resistant toall weather conditions. It protects the vent pipe construction fromleakage and always prevents rain water from entering into any defect inthe caulking or other weather seals inherent in standard vent pipeconstruction.

The gold coloration is obtained by incorporating gold flakes into thepolypropylene plastic and this material deflects ultra violet rays. Itshould be particularly noted that the manufacture of the device of amaterial and of a size to produce ready flexibility causes the shield tofit regularly on vent pipe constructions which are irregular on theexterior and are out of round or eccentric because of different wallthicknesses. As hereinbefore mentioned the flaring portion of the shieldhas lines scored thereon at different angles to facilitate trimming thelower edge to an angle corresponding with the roof angle. The trimmingcan readily be effected with a knife.

In FIG. 6 there is shown a modified construction which is particularlyuseful in states where the code requires a very long vent pipe.Therefore in this modification the shield is constructed of two separateparts, an upper part 10a and a lower part 10b. The lower part is ofidentical construction with that shown in FIG. 2 except that the outercylindrical portion 22 extends upwardly from the flaring skirt portion23 for a short distance only and terminates in an edge 22b. The upperpart 10a has its outer cylindrical portion 220 of slightly largerdiameter than the lower cylinder 22 terminating in a lower edge 22c. Theupper part 10a telescopically engages the lower part 10b as illustrated.This construction is adapted to fit various lengths of vent pipe by thesliding fit of the two parts. In this modification the upper part 10a isprovided with the inner cylinder 24 integrally connected by the top end25.

What I claim as my invention is:

1. A shield for protecting a roof vent pipe comprising an outercylindrical sheath having its upper end inturned to form an integralinner cylinder, said inner cylinder extending lengthwise of said outersheath and spaced therefrom to provide an annular space for receiving aroof vent pipe, said outer sheath extending for a substantial lengthwisedistance downwardly from said upper end with substantially uniform outerdiameter and substantially uniform thin wall thickness, said innercylinder extending downwardly from said upper end for a distancesubstantially greater than said outer diameter of said outer cylinder,said inner cylindrical sheath also having substantially uniform thinwall thickness and substantially uniform inner diameter, a flaringportion extending downwardly from and integral with said sheath, saidflaring portion being annular in cross section with sides which arestraight in longitudinal section extending at a constant angle for theentire flaring length, said flaring portion terminating in a lower edgelying in a plane extending at an angle with the longitudinal axiscorresponding to the angle of roof with which said vent pipe isassociated.

2. A shield for protecting a roof vent pipe according to claim 1 inwhich said roof vent pipe projects through a metal base having a flatportion engaging a roof, a collar surrounding said pipe, and adome-shaped connection between said flat portion and said collar, saidlower edge of the flaring portion of said shield being flexible andsnugly engaging said dome in a line contact above the flat portion ofsaid base.

3. A shield according to claim 2 in which said flaring portion isprovided with a series of circumferential lines respectively lying in aseries of different planes at different angles with respect to thelongitudinal axis of said shield thereby providing indicia for trimmingsaid flaring portion to obtain a lower edge of desired angularity to fita predetermined roof.

4. A shield for protecting a roof vent pipe according to claim 2 inwhich the entire structure is composed of a molded polypropylene plasticthereby providing a rust-free lightning insulator, said plastic havingincorporated therein gold flakes, in which said flaring portion isprovided with a series of circumferential lines respectively lying in aseries of different planes at different angles with respect to thelongitudinal axis of said shield thereby providing indicia for trimmingsaid flaring portion to obtain a lower edge of desired angularity to fita predetermined roof.

5. A shield according to claim 1 in which the entire structure iscomposed of a molded polypropylene plastic thereby providing a rust-freelightning insulator.

6. A shield according to claim 1 in which said entire structure iscomposed of a molded polypropylene plastic.

7. A shield for protecting a roof vent pipe according to claim 6 inwhich said roof vent pipe projects through a metal base having a flatportion engaging a roof, a collar surrounding said pipe, and adome-shaped connection between said flat portion and said collar, saidlower edge of the flaring portion and said shield being flexible andsnugly engaging said dome in a line contact above the flat portion ofsaid base and in which said flaring portion is provided with a series ofcircumferential lines respectively lying in a series of different planesat different angles with respect to the longitudinal axis of said shieldthereby providing indicia for trimming said flaring portion to obtain alower edge of desired angularity to correspond with the pitch of apredetermined roof. v

8. A shield according to claim 1 in which said flaring portion isprovided with a series of circumferential lines respectively lying in aseries of differentplanes at different angles with respect to thelongitudinal axis of said shield thereby providing indicia for trimmingsaid flaring portion to obtain a lower edge of desired angularity to fita predetermined roof.

9. A shield according to claim 1 in which the intersection of saidsheath with the depending flaring portion is provided on the interiorsurface thereof with a series of protuberances forming abutments tofacilitate integral with said inner cylinder.

1. A shield for protecting a roof vent pipe comprising an outercylindrical sheath having its upper end inturned to form an integralinner cylinder, said inner cylinder extending lengthwise of said outersheath and spaced therefrom to provide an annular space for receiving aroof vent pipe, said outer sheath extending for a substantial lengthwisedistance downwardly from said upper end with substantially uniform outerdiameter and substantially uniform thin wall thickness, said innercylinder extending downwardly from said upper end for a distancesubstantially greater than said outer diameter of said outer cylinder,said inner cylindrical sheath also having substantially uniform thinwall thickness and substantially uniform inner diameter, a flaringportion extending downwardly from and integral with said sheath, saidflaring portion being annular in cross section with sides which arestraight in longitudinal section extending at a constant angle for theentire flaring length, said flaring portion terminating in a lower edgelying in a plane extending at an angle with the longitudinal axiscorresponding to the angle of roof with which said vent pipe isassociated.
 2. A shield for protecting a roof vent pipe according toclaim 1 in which said roof vent pipe projects through a metal basehaving a flat portion engaging a roof, a collar surrounding said pipe,and a dome-shaped connection between said flat portion and said collar,said lower edge of the flaring portion of said shield being flexible andsnugly engaging said dome in a line contact above the flat portion ofsaid base.
 3. A shield according to claim 2 in which said flaringportion is provided with a series of circumferential lines respectivelylying in a series of different planes at different angles with respectto the longitudinal axis of said shield thereby providing indicia fortrimming said flaring portion to obtain a lower edge of desiredangularity to fit a predetermined roof.
 4. A shield for protecting aroof vent pipe according to claim 2 in which the entire structure iscomposed of a molded polypropylene plastic thereby providing a rust-freelightning insulator, said plastic having incorporated therein goldflakes, in which said flaring portion is provided with a series ofcircumferential lines respectively lying in a series of different planesat different angles with respect to the longitudinal axis of said shieldthereby providing indicia for trimming said flaring portion to obtain alower edge of desired angularity to fit a predetermined roof.
 5. Ashield according to claim 1 in which the entire structure is composed ofa molded polypropylene plastic thereby providing a rust-free lightninginsulator.
 6. A shield according to claim 1 in which said entirestructure is composed of a molded polypropylene plastic.
 7. A shield forprotecting a roof vent pipe according to claim 6 in which said roof ventpipe projects through a metal base having a flat portion engaging aroof, a collar surrounding said pipe, and a dome-shaped connectionbetween said flat portion and said collar, said lower edge of theflaring portion and said shield being flexible and snugly engaging saiddome in a line contact above the flat portion of said base and in whichsaid flaring portion is provided with a series of circumferential linesrespectively lying in a series of different planes at different angleswith respect to the longitudinal axis of said shield thereby providingindicia for trimming said flaring portion to obtain a lower edge ofdesired angularity to correspond with the pitch of a predetermined roof.8. A shield according to claim 1 in which said flaring portion isprovided with a series of circumferential lines respectively lying in aseries of different planes at different angles witH respect to thelongitudinal axis of said shield thereby providing indicia for trimmingsaid flaring portion to obtain a lower edge of desired angularity to fita predetermined roof.
 9. A shield according to claim 1 in which theintersection of said sheath with the depending flaring portion isprovided on the interior surface thereof with a series of protuberancesforming abutments to facilitate ejection from a molding machine.
 10. Ashield for protecting a roof vent pipe according to claim 1 in whichsaid outer sheath is constructed of two separate parts telescopicallyengaging each other, the lower part with said flaring portion having itsouter cylindrical sheath terminating a short distance above said flaringportion, and the upper part having its outer cylindrical sheath ofslightly larger diameter to telescopically engage said lower part, saidupper part being integral with said inner cylinder.